Art of packing



Oct. 20, 1942. HULTKRANS 2,299,699

ART OF PACKING Filed Spt. 28, 1940 3 Sheets-Sheet l ATTORNEY.

Oct. 20, 1942. p HULTKRANS 2,299,699

ART OF PACKING Filed Sept. 28, 1940 3 Sheets-Sheet 2 ATTORNEY.

1942- P. B. HULTKRANS ART OF PAIKING 3 Sheets-Sheet 5 Filed Sept. 28, 1940 pg V NTOR 77 BY ,WW/mw ATTORNEY- Patented Oct. 20, 1942 ART OF PACKING Paul B. Hultkrans, Milwaukee, Wis., assignor to Milprint, Inc., of Delaware Milwaukee, Wis., a corporation Application September 28, 1940, Serial No. 358,859

Claims.

The present invention relates in general to improvements in the art of packing various commodities in sealed wrappers, and relates more specifically to an improved method of and apparatus for effecting the closure and sealing of diverse packages and especially cartons having linings formed of heat scalable sheet material.

An object of the invention is to provide an improved method of packing and improved apparatus for carrying on the new method.

It has heretofore been proposed to pack batches of diverse commodities in individual Wrappers each comprising an outer box formed of cardboard or the like, and having therein a tubular lining of relatively flexible sheet material such as Pliofilm either loosely confined or permanently attached within the relatively rigid carton, the ends of the lining tube being sealed in some manner to hermetically enclose the batches. While sheet materials such as Pliofilm are adapted to be readily heat sealed, considerable difficulty has heretofore been encountered in handling such relatively thin and delicate wrapping stocks, and in preventing contacting and adhesion of the inner surfaces of the tube walls'due to static electrification; and it was therefore diificult to'produce uniformly regular successive packages having desired capacity and in which the product was neatly and effectively confined and sealed. Because of the frail nature and peculiar characteristics of the thin transparent lining material and the difficulties encountered in handling the same, the previous use of this desirable wrapping stock also resulted in considerable waste of material and loss of time, thus making the cost prohibitive in many cases. While various methods have heretofore been proposed for obviating these difficulties, none of these prior methods and apparatus have proven commercially satisfactory.

It is therefore a more specific object of my present invention to provide a new and useful method of handling and of sealing commodities in relatively thin and delicate wrapping stock, and especially such stock when adapted to be sealed by the application of heat.

Another specific object of my invention is to provide simple and efiicient apparatus for effecting rapid and effective sealing of packages wrapped with Pliofilm or the like.

A further specific object of the present invention is to provide a simple, compact and readily manipulable machine for eifecting hermetic sealing of successive boxes having tubular linings of fusible material.

Still another specific object of the invention is to provide an improved sealing unit for effecting rapid and efiicient heat sealing of tubular or bag-like wrappers formed of transparent sheet 5 material such as Pliofilm or the like, which is normally rather diificult to handle.

An additional specific object of my invention is to provide a new method of and apparatus for durably packing and for hermetically sealing diverse commodities with minimum waste of ma terials and at relatively low cost.

These and other specific objects and advantages of the present invention will be apparent from the following detailed description.

A clear conception of the several steps constituting my new method, and of the construction and operation of one of my improved packing machines, may be had by referring to the drawings accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. 1 is a perspective view of the major portion of one of my improved packaging machines, showing the carton supporting and lining spreader arms disposed for reception of a fresh carton and with the spreader fingers and heater inactive;

Fig. 2 is a similar perspective view of the machine of Fig. 1, showing the lining spreader arms in active position, and also showing the spreading fingers in active position but the heater still inactive;

Fig. 3 is another similar perspective view of a part of the same machine, showing the spreader arms and fingers and the heat sealer, all in active position;

Fig. 4 is a side elevation of one of the improved packaging machines, with the spreader arms,

spreader fingers and the heat sealer, all in active position; i

Fig. 5 is a partial top View of the machine of Fig. 4, some of the elements having been omitted for clearness;

Fig. 6 is a front view of the assemblage of Figs. 4 and 5;

Fig. 7 is a somewhat diagrammatic side view of the spreader arms, showing a carton in section initially applied to the arms, and depicting the first step of my improved method;

Fig. 8 is a view similar to that of Fig. 7, but showing the arms in spreading position, and depicting the second step of the method;

Fig. 9 is a fragmentary diagram showing the upper portion of the assemblage of Fig. 8 but with the spreader fingers in action, and depicting the third step of my method;

Fig. is a fragmentary section taken through the diagram of Fig. 9 and illustrating the action of the spreader fingers;

Fig. 11 is a view similar to that of Fig. 10 showing the heat sealer in action, and depicting the fourth step of the improved sealing method;

Fig. 12 is another view similar to that of Figs. 10 and 11, and showing the final step of closing the sealed carton; and

Fig. 13 is a perspective view of a support for maintaining the carton in position after one end has been sealed, and preparatory to loading and opposite end sealing thereof.

While the invention has been shown and described herein as being especially applicable for the purposes of sealing rectangular cardboard cartons lined with thin transparent heat-scalable sheet material such as Pliofilm or the like, it is not my desire or intent to thereby unnecessarily restrict the scope or utility of the improvement.

In accordance with my present invention, I produce a package by first uniting the opposite edges of a wrapping sheet to form a tube 15, next I distend one of the mouth portions is of the tube so as to bring the opposite internal surfaces thereof closely adjacent to each other, and finally I press the adjacent surfaces together to form a seal l1 extending entirely across the adjacent tube mouth. When the wrapping material is thin and extremely pliable and rather frail, it is preferable to mount the tube to within a boX or carton if! of relatively stiff sheet material such as cardboard; and if the wrapping sheet material is heat scalable, I apply heat when forming the pressed seal ll. When one end of the tubular wrapper has been thus sealed, the load may be inserted and the opposite end may be likewise sealed, see Figs. '7 to 13 inclusive. I provide suitable apparatus for performing all of these steps in order to facilitate commercial ex-. ploitation of my improved method, but this apparatus may be varied in structure to meet different conditions.

V Referring to Figs. 1 to 6 inclusive, the improved apparatus shown therein is adapted to facilitate exploitation of the new method, and comprises in general a base having a central guideway 22! thereon and opposite side frames 22', 23 extending upwardly therefrom; a transportable conveyor or plate 2 1 slidable along the guideway 2i and having a pair of spreader arms '25, 2B swingably secured thereto by means of hinges 27, the arms being interconnected by an adjustable link 28; a pair of spreader fingers 29, 33 suspended from pivot shafts 3|, 32 journalled inthe frames 22, 23, which shafts are interconnected by a link 33 coacting with cranks 34, 35 secured to the shafts ill, 32 respectively; a pair of cooperable jaws 35, Bl swingably suspended upon pivot shafts 38, 39 carried by the side frames 22, 23 and having a rubber anvil 4i! and an electrically heated sealing edge M respectively; a transverse actuating shaft 42 rotatably journalled in the frames 22, 23 and having anarm 43 swingably suspended therefrom and cooperating with the pivot shaft 3! through a crank 44; and cranks 45, d8 secured to the ends of the actuating shaft 42 and coacting through slotted links l'i, 8 with the jaws 3B, 31, one of said cranks being provided with an actuating handle 49.

The base 29, guideways 2i, and frames 22, 23, maybe formed of structural metal bars welded be a section of an intermittently movable conveyor adapted to feed successive sets of spreader arms 25, 26 to and from the sealing machine. When the arms 25, are in upright or spreading position, they are approximately parallel to each other; but when these arms are swung down as in Figs. 1 and 7, they converge at the top so that the tubular wrapper may be readily slipped thereover. The link l8 may be provided with a turn buckle 50 as shown, in order to permit relative adjustment of the arms 25, 26, and the arm 26 is also provided with a stop flange 5! for properly positioning the wrapper assemblages relative to the fingers 29, 38 and to the heat sealing jaws 36, 3?. In addition to the conveyor or plate 24 having the spreader arms 25, 26 thereon for initially supporting the wrapper, I also provide another conveyor or plate 52 which is slidably cooperab-le with the guideways 2|, and has a stand ard 53 thereon provided with a box support 54 and retaining plates 55, 55 as illustrated in Fig. 13. This auxiliary supporting assemblage may likewise be a section of another intermittently movable conveyor adapted to feed successive boxes having one end thereof sealed, through a loading or filling mechanism, and finally to and from another sealing machine; and the support 54 and spring plates 55, 58 are adapted to hold the box assemblage in upright position during loading and final sealing.

The link 33 and the cranks 35, which interconnect the spreader finger supporting shafts El, 32, are so formed that they swing the fingers 29, 3% simultaneously but in opposite directions; and the fingers are constantly urged toward spreading position by means of a coil spring 5? embracing the shaft &2 and having its opposite ends connected to the side frame 22 and to the lever arm 4-3 respectively. The swinging end of the arm 43 has a slot 58 therein, cooperating with a pin 59 carried by the swinging end of the acfltuating crank 44 which is secured to the shaft 3!; and the manually operable crank t5 is rigidly secured to the operating shaft '52 and carries an abutment Ell which is adapted to engage the lever arm 43 when the handle 49 is released. A relatively strong tension spring '5! connects the extreme swinging end of the crank 65 with the side frame 22, and this spring 6i swings the crank 45 down and the handle 49 up, whenever the later is released. When the crank G5 is thus lowered, the abutment 60 swings the arm &3 and the crank M down, thus swinging the fingers 2%, 39 toward each other; but when the handle dB is lowered to elevate the crank 45, then the abutment 69 is also elevated and the spring 51 quickly becomes effective to spread the fingers 2Q, 30.

The crank it, like the crank 45, is also rigidly secured to the operating shaft 52, and the links 47, 48 which connect these cranks 35, 40 with the jaws 3B, 31 respectively, are slotted as shown. The jaws 36, 31 are provided with arms 62 having pins 63 which coact with the slots M in the 5 links 41, &8, and other tension springs 85 connect the pins 63 with the adjacent side frames 22, 23 and constantly tend to separate the jaws 3B, 31, see Fig. 6. The sealing jaws are thus normally separated, but when the handle 49 is lowered to initially separate the spreader fingers 29, 38; continued downward movement of the handle 59 will ultimately cause the links M, 48 to engage the pins 63 and to swing the jaws 3f, 38 toward each other about their pivot shafts or otherwise firmly united, and the plate 24 may 38, 39. The longitudinal strip or anvil to which is carried by the jaw 36 may be formed of pliable material such as rubber, and the elongated sealing edge portion M of the other jaw 31 may be heated electrically by means of a heater 6'6 and control mechanism 61, or otherwise. Various parts of the assemblage may be made readily adjustable to cause the parts to properly cooperate with each other during normal operation.

When the improved machine has been properly constructed, assembled and adjusted, it may be used advantageously for the purpose of carrying on my improved method, and the successive tubular wrappers or tubes I should first be formed and secured within cartons or boxes I8, each having side folding fiaps 58, and a closure flap 69 at each of its opposite ends. The opposite end or mouth portions I6 of the tubes I5 should project from the opposite ends of the boxes I8, substantial distances; and while the boxes I8 when empty, may be collapsed or flattened for storage and shipment, the lining tubes I5 will be distended when the individual boxes are distended.

During normal operation of the machine and while carrying on my improved method, the successive distended boxes I8 may first be placed over the spreader arms 25, 26 as shown in Fig. 1, so that one of the lower flaps 68 of the box and the adjacent portion I6 engage the stop flange 5| of the arm 26. The arms 25, 26 may then be swung to upright position above the hinges 21, as shown in Fig. 8, thereby causing the outer surfaces of the arms 25, 25 to engage the interior side surfaces of the tube I5 and to firmly hold the box and its lining in distended or spread out condition. The assemblage may then be inserted within the machine between the guideways 2i, and the handle 49 may be subsequently operated to cause the spreading fingers 2S, 3%) to engage the upper projecting portion I6 of the tube I5 and to spread this portion to the position shown in Figs. 9 and 10, while at the same time moving the flaps 68 away from the sealing zone. After this step of the process has been accomplished, the handle 49 may be lowered further, thereby causing the links 4?, 43 to move the jaws 36, 31 inwardly toward each other directly beneath the lower extremities of the fingers 29, 30. By continuing the downward movement of the handle 49, the jaws 31 will be brought into coaction with the opposite sides of the taut tube portion I6, as illustrated in Fig. 11, and a heat seal I'I will be formed completely across the top of the tube I5. The adjacent tube portion I6 may then be folded to the position shown in Fig. 12, the side flaps 68 may be folded inwardly, and the closure flap 69 may be finally inserted within the box II! to complete the seal at that end of the box. The initially sealed box I8 may then be removed from the spreader arms 25, 26 by merely tilting these arms about the hinges 21 and slipping the box therefrom. The initially sealed box I8 may be subsequently set upon the support 54 of the auxiliary conveyor or plate 52, between the resilient retainer plates 55, 56 as indicated in Fig. 13, whereupon material may be inserted within the bag or tube I5, and the opposite projecting portions I6 may be likewise sealed in the improved machine. In this manner, both ends of the tubular wrapper and of the reinforcing box I8 may be hermetically sealed to effectively confine the commodity, and the several steps may be quickly repeated with respect to successive wrappers.

From the foregoing detailed description it will be apparentthat my present invention provides a method of quickly and effectively hermetically sealing successive tubular wrappers, especially when these wrappers are inserted within a reinforcing box or carton so as to provide a lining for the latter. In accordance with the improved method, the mouth portion of the tubular wrapper is distended so as to bring the opposite internal faces thereof closely adjacent to each other, and the seal is formed by merely pressing these surfaces together adjacent the mouth of the opening. By. utilizing heat scalable material, electric heaters may be effectively utilized to quickly produce the seal and both ends of a tube may be sealed in rapid succession. The improved machine is extremely effective in carrying on the new method because of the fact that the fingers 29, '36 function quickly to distend the mouth portion of the tube, and the sealing jaws 36, 3'! follow the operation of the spreading fingers 29, 36 very quickly. After a wrapper has been sealed with the improved machine, quick release of the wrapper is made possible by the action of the several springs which restore the mechanism to inactive position whenever the lever 49 is released. As previously indicated, the capacity of the machine may be enhanced by providing endless conveyors upon which the arms 25, 26 and the standards 53 are mounted, and the handle 49 may be operated either by hand or foot, or in any other manner. The improved method and machine have proven highly successful in actual commerciaLuse, especially in conjunction with materials such as Pliofilm, which are heat sealable without the use of adhesive. However, the method may be utilized in conjunction with adhesive and may also be utilized in conjunction with wrappers which are not necessarily confined within an outer reinforcing box. By stretching the mouth portions transversely before sealing, wrinkling of the stock is avoided and more perfect seals are produced and the fingers also remove the flaps 66 from the sealing zone when they are active in stretching. lhis stretching of the mouth portion of the tubular wrapper is extremely important as it places the two opposite inner surfaces of the sheet in stretched and smooth condition closely adjacent to each other, and subsequent formation of the seal can be effected with minimum heating. The stretching and resultant smoothing is accomplished automatically and quickly by the fingers 29, 30 which are so positioned that they do not obstruct the subsequent action of the heat sealing jaws.

It should be understood that it is not desired to limit this invention to the exact details of construction or to the precise steps of the method, herein shown and described, for various modifications within the scope of the claims may occur to persons skilled in the art.

I claim:

1. In combination, a pair of pivotally mounted spreader arms insertible within a tubular Wrapper and being relatively separable during swinging thereof to distend the wrapper into approximately rectangular shape, a pair of fingers insertible within the end of the distended tube remote from said arms, means for spreading said fingers to stretch said tube end transversely beyond the arms, and a pair of pivotally suspended sealing jaws swingable against the outer portion of the tube beyond said arms and closely adjacent to the free ends of said fingers to produce a final seal extending across the tube.

2. In combination, a pair of swingable and simultaneously separable arms insertible within a tubular wrapper'and being movable to distend the wrapper into approximately rectangular shape, spreading fingers insertible into the mouth of the tube beyond the ends of said arms and being movable to stretch the tube mouth to approximately closed condition, and a pair of jaws having narrow elongated edge portions simultaneously movable against the outer surfaces of the stretched mouth portion of the tube closely adjacent to the free ends of said fingers to produce a final seal extending across the tube.

3. In combination, a pair of swingable and simultaneously separable arms insertible within a tubular wrapper and being movable to distend the wrapper into approximately rectangular shape, spreading fingers insertible into the mouth of the tube beyond the ends of said arms and being movable to stretch the tube mouth to approximately closed condition, and a pair of pivotally suspended jaws swingable in unison against the outer surfaces of the stretched mouth portion of the tube closely adjacent to the free ends of said fingers to produce a final seal extending across the tube.

4. In combination, a pair of pivotally suspended arms simultaneously swingable and separable and being insertible within a collapsible box lined with a tubular wrapper and movable to distend the box and lining tube into approximately rectangular shape, means for drawing the end of the lining tube beyond the ends of said arms into approximate closed condition, and a pair of pivotally suspended jaws simultaneously swingable against the closed tube portion to produce w a final seal extending across the tube beyond the box end.

5. In combination, a pair of arms insertible within a tubular Wrapper to distend the same, a pair of fingers insertible within the tube end remote from the ends of said arms, means for separating said fingers to stretch the adjacent tube end, and a pair of jaws simultaneously swingable against the outer surfaces of the stretched tube end closely adjacent to the free ends of said fingers to provide a final seal ex tending across the tube.

6. The method of packing, which comprises, in-

serting a pair of arms Within one of the open ends of a tubular wrapper and moving the inserted arms away from each other to distend the wrapper into approximately rectangular shape, stretching the opposite open end of the rectangular tube so as to collapse and approximately close said end, and finally pressing and heat sealing said closed tube end along a transverse area while the stretching operation is still in progress.

7. The method of packing, which comprises, inserting a pair of arms Within one of the open ends of a tubular wrapper and moving the inserted arms apart to distend the wrapper into definite prismatic shape, stretching the opposite open end of the prismatic tube so as to collapse and approximately close said end, and finally pressing and sealing said collapsed tube end along a transverse area while the distorting and stretching operations are still in progress.

8. In combination, a pair of arms insertible within one end of a tubular wrapper and being separable to distend the wrapper into definite prismatic shape, means insertible within the opposite end of the tube and being operable to stretch said opposite end into collapsed condition, and a pair of sealing jaws cooperable with the wrapper between said distending arms and said stretching means.

9. In combination, spreader arms insertible in one end of a tubular wrapper and being separable to distend the wrapper from within into definite prismatic shape, spreader fingers insertible within the opposite end of the tube and being separable stretch said opposite end into collapsed condition, and means cooperable with the exterior of said wrapper between said arms and said fingers for transversely sealing the tube.

10. In combination, spreader arms insertible through the lower open end of an upright tubular Wrapper and being separable to distend the wrapper into definite prismatic shape, a pair of fingers suspended above the upper open end of the tube and being separable to collapse said upper end, and a pair of sealing jaws pivotally suspended below the upper ends of said arms and the lower ends of said fingers and being cooperable to transversely seal the tube below the finger tips.

PAUL B. HULTKRANS. 

